50 Lehoux
the tips of the fi ngers... But I have not yet told why they were made just
so hard and no harder or why they are rounded on all sides, but now is the
proper time to do so.^30And so on for two full pages: they are just fi rm enough to offer resis-
tance without being brittle; they cushion blows to the backs of the fi ngers;
they are rounded so that parts do not break off; they grow in length but
not in width because only the ends wear away. “Thus everything about
the fi ngernails shows the utmost foresight on the part of Nature.”^31 The
modern reader may be forgiven for fi nding Galen’s paean to the fi nger-
nail strange to the point of being almost amusing, but the reader’s hasty
amusement is quickly trumped by respect as Galen proceeds to expose and
explain the internal structures of the hand in the most rigorous, skilled,
and sophisticated manner. In all cases, though, and at all levels, the struc-
ture of the hand is goal- driven. Not only this, but the extreme complexity
of the living organism, and this incredible match between structure and
function in all its parts, leads Galen to conclude that not only is nature
purpose- driven, but that Nature (and here it seems best to capitalize the
“N”) is also deliberately providential—a divinity that has rationally and
consciously shaped the structures of the bodies to be best suited to their
particular ends. He moves from teleology to theology and back again,
and the argument for a providential divinity both guides his inquiry and
frames his understanding of the whole.
By providing a window through which Galen saw his subject, the
providence of Nature at one and the same time feeds into how he sees,
as well as providing an incentive for undertaking increasingly diffi cult,
increasingly careful, and increasingly invasive observation. I do not wish
to suggest that it provides the only such reason (prestige and public per-
formance, for example, also play large roles),^32 but it does stand in a po-
tent feedback relation to Galen’s observational project as a whole. The
temptation from a modern perspective is to see the imposition of a per-
sonifi ed deity as interfering in the pursuit of objectivity, but if anything
the converse is true. Galen was not seeking his own justifi cations for the
usefulness of the parts of the body, he was seeking Nature’s. This forced
him to take as broad and unencumbered a stance as possible in order to
see what the roles of a part in the overall physiological system might be,
and to try and catalog and understand not just the obvious function of the
part but all the functions, especially the hidden ones. We may today want
to replace Galen’s deifi ed Nature as an explanatory mechanism, with a
depersonifi ed natural selection, but the end products (the fi ngernails, the